Method of making glass structures for flat panel displays

ABSTRACT

An assembly of rib structures sandwiched between a dielectric glass layer and a glass substrate for use in a flat panel display, such as plasma addressed liquid crystal (PALC) displays, is formed by a number of methods. One method includes molding thermoplastic glass frit containing paste into rib structures, transferring the rib structures to a thin transparent layer of a thermoplastic dielectric glass frit containing composition on a drum, and transferring the rib structures with the thin transparent dielectric glass layer to a glass substrate having metallic electrodes already formed thereon.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application discloses subject matter related to co-pendingapplications “OPAQUE RIB STRUCTURES FOR DISPLAY PANEL” filed on Dec. 21,1998, as European Patent Application No. 98403244.1 and on Jan. 25, 1999as U.S. application Ser. No. 60/117,158; and U.S. application Ser. No.08/820,206 filed Mar. 18, 1997 now U.S. Pat. No. 5,853,446; thedisclosures of which are incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to the field of flat panel displays, and inparticular, to a method of manufacturing plasma addressed liquid crystal(PALC) displays.

BACKGROUND INFORMATION

Flat panel displays, e.g., liquid crystal displays, are known. Recently,the use of plasma channels to address a liquid crystal display (LCD) hasbecome known. For example, U.S. Pat. Nos. 4,896,149, 5,036,317,5,077,553, 5,272,472, 5,313,223, the disclosures of which are all herebyincorporated by reference, each disclose such a structure. This type ofdisplay technology provides an active addressing matrix suitable forhigh-line-count displays, and is competitive alternative to the knownthin-film transistor (TFT) active matrix approach.

These plasma channel panels are also referred to herein as plasmaaddressed liquid crystal (PALC) displays. This type of plasma displaypanel is generally formed of two parallel substrates separated from eachother to form a discharge space between the substrates, which contains adischarge gas, such as a mixture of helium, neon and xenon. Theinner-facing surface of each of the substrates bears a pattern of spacedparallel electrodes, with the electrodes on one substrate beingoriented, for example, in a direction orthogonal to the direction of theelectrodes on the other substrate. The electrode bearing surfaces of thesubstrates are typically covered with a dielectric layer, and red, greenand blue phosphors are separately located in discrete areas on theinternal surface of the dielectric layer on one of the two substrates.The dielectric layers are generally lead-based glass frits fired between500 and 600° C., depending on their formulation and the level ofuniformity required. The displayed picture is produced by plasmadischarges which are induced locally in the gas by applying a suitablevoltage between the electrodes of one substrate and the electrodes ofthe other substrate. Ultraviolet light emitted locally by the gasdischarge induces luminescence of the neighboring phosphors.

A PALC display relies on the highly non-linear electrical behavior of arelatively low pressure (e.g., 10 to 100 Torr) gas, e.g., He, confinedin parallel channels. A cross section of a portion of a PALC display 100is shown in FIG. 1. A pair of parallel electrodes 101A (anode) and 101C(cathode) is deposited in each channel 102 on a rear glass plate 101G,for example, forming the bottom of the channels, and a very thindielectric sheet 103, e.g., a glass micro-sheet of about 50 μmthickness, forms the top of the channels 102. A liquid crystal layer 104on top of the micro-sheet 103 is the optically active portion of thedisplay 100. A cover sheet 105, e.g., a passive glass plate of about 1.1mm, with transparent conducting electrodes, e.g., made from indium-tinoxide (ITO), running perpendicular to the plasma channels 102, lies ontop of the liquid crystal 104. Conventional polarizers 106, colorfilters 107, and back lights 108, like those found in other conventionalliquid crystal displays, are also commonly used, as illustrated.

When voltages are applied to the transparent electrodes, since there isno ground plane, the voltages are divided among the liquid crystal, themicro-sheet, the plasma channel, and any other insulators interveningbetween the transparent electrode and whatever becomes the virtualground. As a practical matter, this means that if there is no plasma inthe plasma channel, the voltage drop across the liquid crystal will benegligible, and the pixels defined by the crossings of the transparentelectrodes and the plasma channels will not switch. If, however, avoltage difference sufficient to ionize the gas is first applied betweenthe pair of electrodes in a plasma channel, a plasma forms in the plasmachannel so that it becomes conducting, and constitutes a ground plane.As a result, for pixels atop this channel, the voltages will be dividedbetween the liquid crystal and the micro-sheet only. This places asubstantial voltage across the liquid crystal and causes the pixel toswitch. Igniting a plasma in the channel causes the row above thechannel to be selected. Because the gas in the channels isnon-conducting until a well-defined threshold voltage between theelectrode pair is reached, the rows are extremely well isolated from thecolumn voltages unless selected. This high non-linearity allows largenumbers of rows to be addressed without loss of contrast.

To avoid luminous cross-talk between neighboring regions and improve thecontrast in such displays, opaque barrier ribs 110 are disposed on atleast one of the substrates (typically the rear one) formingelectrically insulated discharge cells. The barrier rib structure istypically periodic with a pitch of, for example, from 200 μm to 400 μm,depending on the panel resolution. These ribs are, for example, about30-100 μm wide and 100-200 μm thick (i.e., high).

Alternatively, a closed cell design has been employed having squarecells which are about 200-400 μm on each side. The “ribs” which formthese square cells are about 30 μm to 70 μm wide and about 30 to 200 μmhigh. Plasma panels of this type are described, for example, in U.S.Pat. No. 4,853,590, as well as Japanese Patent Application Nos.J04255638 and J04075232. The networks of parallel barrier ribs mentionedabove delimit columns of pixels which can be addressed independently.The two perpendicular networks of electrodes allow ionization of the gasat the selected pixels. The ultraviolet radiation emitted by the ionizedgas causes the excitation of areas of phosphorescent products associatedwith said pixels according to the configuration of an image which is tobe displayed.

The PALC display relies on the use of a thin micro-sheet to separate theplasma from the liquid crystal. This micro-sheet should be as thin aspossible (e.g. 1.5-2 mils), with as high a dielectric constant aspossible, to thereby minimize the voltage drop across it. Currentdisplay manufacturers utilize a single, monolithic piece of micro-sheetfor this purpose, e.g., a D-263 micro-sheet of 30 to 50 μm thicknessmade by Schott. However, these large sheets of glass are difficult tomanufacture, causing the availability of large, thin micro-sheet to be apotential limitation on the size of the PALC displays that can be made.

In the past, the barrier ribs have typically been made either by asilk-screening method, or by sandblasting from a deposited layer offrit. Thus, the channels between the barrier ribs have been made byetching into a glass substrate or by building up walls of glass on asubstrate by deposition processes such as screen-printing. However,etching of the channels typically results in channels having roundedbottoms, while building up material to form walls generally results innon-vertical side walls. Both of these conditions adversely affect lighttransmission through the panel. In addition, the manufacture of ribstructures with a high aspect ratio usually requires multiple processsteps, including polishing the top of the ribs to match the flatness ofthe glass micro-sheet.

Accordingly, a need exists for a method which solves the above problemsand overcomes the limitations of the known manufacturing processes ofPALC displays. There is further a need for a method which achievesimproved structures on the rear glass plate, including metallicelectrodes and high aspect ratio opaque ribs, and which can obtain sucha structure with a thin dielectric glass sheet.

SUMMARY OF THE INVENTION

This invention provides a method for making glass structures for flatpanel displays. This invention further provides a method that solves theabove mentioned problems so that improved structures and lowermanufacturing costs are achieved.

Copending related U.S. application Ser. No. 08/820,206 referenced above,discloses a micro-molding process for the formation of barrier ribs.Incorporation of such micro-molding techniques into the manufacture ofPALC structures, according to the process of the present invention,overcomes many of the disadvantages noted above and provides asimplified process for the manufacture of such structures.

According to an aspect of the invention, a method of manufacturing anassembly of rib structures between glass substrates for use in a plasmaaddressed liquid crystal display includes: (a) providing a mold havingcavities; (b) providing a glass paste into the mold cavities to form therib structures; (c) forming a thin layer of a transparent glass on acollector drum; (d) transferring the rib structures from the mold to thethin transparent glass layer on the collector drum; and (e) transferringthe rib structures and thin transparent glass layer from the collectordrum to a glass substrate.

According to an aspect of the invention, the mold is a soft intagliomold made of a material exhibiting good release characteristics such assilicone. In another aspect of the invention, the mold is a thickperforated sheet made of a material exhibiting good releasecharacteristics such as silicone. In a further aspect of the invention,the glass paste is a glass frit with a curable, settable or hardenable(hereinafter referred to collectively as “curable”) organic binder.

According to another aspect of the invention, the glass substrate hasmetallic electrodes formed thereon by a photo-lithographic technique, ascreen printing technique, a micro-molding technique, or otherconventional method. In a further aspect of the invention, the thintransparent layer of glass comprises a layer of glass approximately 50μm or less in thickness after firing. Another aspect of the inventioninvolves transferring the rib structure from the mold to the thintransparent layer of glass on the collector drum by contact and cooling.

An additional aspect of the invention provides a method of manufacturinga plasma addressed liquid crystal display structure, including: (a)providing a glass substrate; (b) providing a first mold having cavities;(c) providing a metallic paste into the mold cavities to form electrodestructures; (d) transferring the electrode structures to the glasssubstrate; (e) providing a second mold having cavities; (f) providing aglass paste into the second mold cavities to form rib structures; (g)forming a thin layer of transparent glass on a collector drum; (h)transferring the rib structures from the second mold to the thintransparent glass layer on the collector drum; and (i) transferring therib structures and thin transparent glass layer from the collector drumto the surface of the glass substrate bearing the electrodes.

These and other aspects of the invention will become apparent from thedetailed description set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a cross-sectional view of a Plasma Addressed LiquidCrystal (PALC) display.

FIGS. 2A to 2K illustrate method steps according to an exemplaryembodiment of the invention for preparing PALC displays.

FIGS. 3A and 3B illustrate providing a metal core and adding a bridgestructure according to an exemplary embodiment of the invention.

FIG. 4 illustrates an exemplary arrangement for practicing a methodaccording to an exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention will now be described in more detail by way of examplewith reference to the embodiments shown in the accompanying figures. Itshould be kept in mind that the following described embodiments are onlypresented by way of example and should not be construed as limiting theinventive concept to any particular physical configuration.

FIG. 1 illustrates a cross-sectional view of a Plasma Addressed LiquidCrystal (PALC) display, which has been briefly discussed in theBackground section of this disclosure. A pair of parallel electrodes101A (anode) and 101C (cathode) is deposited in each channel 102 on arear glass plate 101G, for example, forming the bottom of the channels,and a very thin dielectric sheet 103, e.g., a glass micro-sheet of about50 μm, forms the top of the channels 102. A liquid crystal layer 104 ontop of the micro-sheet 103 is the optically active portion of thedisplay 100. A cover sheet 105, e.g., a passive glass plate of about 1.1mm, with transparent conducting electrodes, e.g., made from indium-tinoxide (ITO), running perpendicular to the plasma channels 102, lies ontop of the liquid crystal 104. Conventional polarizers 106, colorfilters 107, and back lights 108, like those found in other conventionalliquid crystal displays, are also commonly used, as illustrated. Opaqueribs 110 separate the channels 102.

FIGS. 2A to 2K illustrate method steps according to an exemplaryembodiment of the invention, in particular, a method of manufacturing acomplete PALC structure through a continuous manufacturing process. Thecomplete PALC structure may include an optional dielectric barrier layer202 on a glass substrate 201.

In this exemplary method, the formation of the plasma channel structure,with or without an optional glass frit dielectric barrier layer 202 onthe glass substrate 201, may be achieved in a continuous process. Forthis exemplary method, the materials used may include: electrodematerials made of, for example, a metallic powder dispersed in a curableorganic medium (e.g., silver powder dispersed in a thermoplastic waxmedium); dielectric glass frit materials made of, for example, a glasspowder dispersed in a curable organic medium (e.g., a thermoplastic waxmedium) which materials are transparent; and rib materials made of, forexample, a glass powder dispersed in a curable organic medium (e.g., athermoplastic wax medium), which can be made opaque by the inclusion ofopaque pigments. Useful curable media should be micromoldable and easilyremoved by burning, and include both thermoplastic and thermosettingmaterials. However, thermoplastic materials are often generallypreferred.

Referring to FIG. 2A, Step 1, depending on the nature of the glasssubstrate 201 used, an optional dielectric glass paste 202 may be bladedonto a glass substrate 201. The glass paste preferably contains athermoplastic binder material and can be softened by heating prior toapplication to the glass substrate. The inclusion of the dielectriclayer 202 can help the transfer of the electrodes from the silicone moldto the glass substrate in Step 3, below, but is not required.Additionally, depending on the composition of dielectric layer 202, itcan also be used as a barrier layer to avoid diffusion of metal oxidesfrom the electrode materials into the glass substrate, which canpotentially make short circuits after long term use of the display.

Step 2, shown in FIG. 2B, illustrates blading a silver electrode paste203 onto an intaglio mold 204. The silver paste 203 will form electrodesat locations which are determined by the arrangement of the cavities orrecesses in the mold 204. The silver paste preferably contains athermoplastic binder and can be softened by heating prior to applicationto the mold. The mold is preferably formed of a soft material exhibitingsuitable release characteristics such as, for example, silicone.

Step 3, illustrated in FIG. 2C, shows a transferring of the silver pasteelectrodes 203 to the glass substrate 201, with or without barrierdielectric layer 202, by pressing the mold 204, having silver pasteelectrodes 203 contained within the cavities therein, against the glasssubstrate 201 with a transfer roll 205 such that the electrodes 203contact the glass substrate 201 and adhere thereto, upon cooling theglass substrate 201 and mold 204. Thereafter, in Step 4, illustrated inFIG. 2D, the mold 204 is released and removed at, e.g., roomtemperature, leaving the electrodes 203 disposed in position on theglass substrate 201, with or without barrier dielectric layer 202.

It should be noted that the above-described process steps 1 to 4 couldbe replaced by any way of printing electrodes onto a coated or un-coatedglass substrate, including a suitable process based onphoto-lithography, a screen printing, or by a micro-molding processutilizing an intaglio collector drum or intaglio mold as disclosed inU.S. Pat. application Ser. No. 08/820,206 referred to above, forexample, as would be understood by those skilled in the art to be withinthe spirit and scope of the invention.

Step 5, illustrated in FIGS. 2E and 2F, shows a first rib forming stepwhich can be accomplished in either of the exemplary illustrated ways.FIG. 2E shows a first alternative in which a dielectric glass paste 207,which can be made opaque according to co-pending application Ser. No.60/117,158 entitled “Opaque Ribs Structures for Display Panel,” filedJan. 25, 1999, used for the rib structure is bladed into a mold 206,e.g., a soft intaglio mold. FIG. 2F shows a second alternative using amold 208 disposed on a flat and rigid substrate 209 for a thick screenprinting technique. In the second alternative of FIG. 2F, rib paste 207is “printed” through slots in the mold 208 onto the rigid substrate 209.In both alternatives, the molds can be formed of any material which canbe patterned with known techniques and which has acceptable releaseproperties, as would be apparent to one skilled in the art, within thespirit and scope of the invention. Preferably, the molds are formed ofsilicone.

Accordingly, in the first alternative of Step 5 shown in FIG. 2E, thesoft intaglio mold 206 would preferably be made of silicone, and theglass paste 207 would preferably be made opaque by using fritcompositions containing opaque pigments. For example, the paste 207could be made of a glass frit, opaque pigments, and a thermoplasticbinder so that the glass paste material can be doctored into the mold ata temperature slightly higher than room temperature, e.g., 50° C. to100° C.

In the second alternative of Step 5 shown in FIG. 2F, where the processof thick screen printing through a mold 208 onto a rigid substrate 209is shown, the method is preferably accomplished as a screen printingtechnique using a thick silicone mold with slots which corresponds tothe rib structures. A possible advantage of this method over theintaglio alternative method of FIG. 2E, resides in the fact that the ribstructure can be filled through the slots of the thick silicone mold 208onto a very rigid and flat substrate 209. This insures a practicallyperfect flatness of the foot of the rib so formed, thereby avoidingnegative meniscus shapes which could occur in the soft intaglio methodalternative after doctor blading, and achieving a better subsequenttransfer onto the glass substrate 201. This second alternative method ofFIG. 2F may also be easier to use when one wants to deposit relativelythick, e.g., 50 to 300 microns thick rib structures directly onto therear glass plate (101G) of the display panel 100.

Step 6, illustrated in FIG. 2G includes coating a transfer drum 210 witha thin layer of transparent dielectric glass paste 211 having a typicalthickness of from about 15 microns to about 50 microns. The transferdrum is preferably formed of a material exhibiting suitable releasecharacteristics to allow removal of the coating layer without damage, oris coated with a suitable release agent or material such as apolyethylene terephthalate (Mylar) film. Further, the glass pastepreferably contains a thermoplastic binder material and the transferroll is preferably heated to a temperature of from about 40° C. to about150° C. to facilitate application of the coating and maintain thecoating in a tacky state sufficient to cause the ribs to release fromthe mold and becomes attached thereto upon contact.

Step 7, shown in FIGS. 2H, 2I, and 2J involves transferring the ribstructure 207 from the mold 206 or 208 onto the coated transfer drum 210by rolling the coated transfer drum over the surface of the mold suchthat the barrier ribs contained within the mold cavities contact thedrum coating and adhere thereto upon cooling. The rib structure 207would, of course, have been previously allowed to consolidate by heatingto a temperature of from about 400° C. to about 600° C. FIG. 2H is theStep 7 alternative which follows from the mold alternative in FIG. 2E,and FIG. 2I is for the Step 7 alternative following from the moldalternative in FIG. 2F. FIG. 2J shows the coated transfer drum 210 withthe rib structure 207 having been transferred thereto. The coating of athin dielectric glass layer 211 contacts the top of the rib structure207.

In Step 8, shown in FIG. 2K, the rib structure 207, with the thindielectric layer 211 on top (from the transfer drum 210), is transferredto the glass substrate 201, with or without the barrier layer 202. Theglass substrate. 201 would already contain the electrodes 203 andoptionally the barrier layer 202, from the previous process stepsdescribed above.

To aid in the transfer onto the glass substrate 201, especially fordesigns where the electrodes 203 are aligned with the rib structure 207,a thin polymer layer, such as an ethyl cellulose layer (not shown), forexample, can be laid down on top of the glass 201 and the electrodes203, to ensure an easy transfer of the ribs 207. This polymer layerfacilitates bonding of the barrier ribs to the substrate by increasingthe adhesion therebetween by providing a tacky, sticky surface. Thispolymer layer would then be eliminated during firing of the wholestructure to fuse the glass frit.

Some advantages of the above-described manufacturing process includecost advantages due to avoiding the multiple steps usually required tomanufacture rib structures with a high aspect ratio by conventionalscreen printing and photolithographic processes, and cost advantages dueto a transfer of the rib structure onto rear glass with electrodes inone step, including a thin dielectric glass layer which replaces theproblematic micro-sheet which is no longer required with this process.This process thus suppresses the need for a large size glassmicro-sheet, and allows thickness reduction of this dielectricseparator, which will improve performances of PALC display panels.Further, excellent contact between the tops of the ribs and the thindielectric glass layer is achieved because the contact is obtained by atransfer process. Consequently, polishing of the top of the ribs, usedusually in PALC structure manufacturing in order to match the flatnessof the glass, is no longer required.

While each of the above micro-molding techniques may be used to form thebarrier ribs and transfer them to the dielectric glass coating on thedrum, avoiding the deposition of a residual film of the barrier ribmaterial on the dielectric glass layer between the ribs can bedifficult. However, in an alternative embodiment of the invention, thisproblem can be avoided by printing the barrier ribs directly onto theglass substrate through a thick screen as described above, and thenapplying a thin layer of a dielectric glass on top of the ribs.

In this method, a thick screen patterned with slots is formed from afilm of a material exhibiting suitable release characteristics such assilicone. The film is deposited on the glass substrate and is preferablyheated to a temperature of from about 40° C. to about 150° C. The glassfrit containing paste for the barrier ribs is then bladed through theslots in the screen onto the glass substrate. After cooling, thepatterned screen is removed to leave the barrier rib structure disposedon the glass substrate. To increase the rigidity of such a thick screen301, and consequently have a better dimensional control over theresulting rib structures, the use of a rigid core structure 302 made of,for example, metal, can be inserted in the patterned screen 301, asshown in FIGS. 3A and 3B. In order to maintain the spacing of the slots,e.g., in the case of long slots required for display applications, thinbridges 303 can be added without obstructing the flow of the glass fritcontaining paste into the slots during the blading operation. FIG. 3Billustrates such a bridge structure 303 according to an exemplaryembodiment of the invention.

A further exemplary method will now be described, which accomplishes thedepositing of a dielectric layer of glass onto rib structures projectingfrom a glass substrate to complete the formation of the plasma channels.The method described in this example demonstrates the basic feasibilityof the use of this embodiment in a continuous manufacturing process,while suppressing the need for large size glass micro-sheet in PALCmanufacturing.

According to this method, a glass substrate with projecting ribs arefirst treated to cure/solidify the ribs prior to deposition of thedielectric glass layer. This can be accomplished by baking the substrateat a temperature of from about 400° C. to about 600° C. to fuse theglass frit and remove the organic binder. However, if the paste used toform the ribs contains a UV-curable medium, consolidation using a UVtreatment is generally sufficient to provide adequate structuralintegrity to the ribs to permit transfer of the dielectric glass layerwithout deformation of the ribs. Thereafter, a layer of a dielectricglass frit containing paste is applied to the tops of the ribs to sealthe plasma channels. The dielectric frit containing layer may bedeposited onto the ribs by transfer from a suitable release substrate.For example, the glass frit containing material may be coated on a filmsuch as polyethylene terephthalate (Mylar) to a desired thickness, suchas from about 15 microns to about 50 microns, and the coatingtransferred onto the tops of the ribs from the release substrate bycontact. Preferably, the glass frit paste contains a thermoplasticbinder and is softened by heating to facilitate application to therelease substrate and adhesion to the tops of the ribs upon contact. Therelease substrate could then be removed after cooling.

FIG. 4 schematically illustrates an exemplary arrangement for practicingthis method according to the described exemplary embodiment of theinvention. In this embodiment, a continuous moving belt 409 comprised ofa release substrate on its surface passes through a heating zone 406 toa cooling zone 408, around a transfer drum 410 and idler roll 411.Thermoplastic glass frit paste 401 is applied to the release substrate409 as it passes around transfer drum 410. The glass frit paste may beapplied by any suitable means, but is preferably formed into a layer ofdesired thickness 402 by a doctor blade 403. Preferably the thickness oflayer 402 is from about 15 to about 50 microns. As belt 409 passesaround transfer drum 410, the layer of glass frit containing material402 contacts the tops 404 of barrier ribs 405 projecting outwardly fromglass substrate 412 which is moving in the direction A therebelow. Asthe glass frit layer passes through the cooling zone 408, it solidifiesand adheres to the tops of the barrier ribs 404. As the belt passesaround idler roll 411, the glass frit containing layer 402 separatesfrom the release surface of belt 409 and is transferred to the ribstructure.

It will be apparent to one skilled in the art that the manner of makingand using the claimed invention has been adequately disclosed in theabove-written description of the preferred embodiments taken togetherwith the drawings.

Further, it will be understood that the above described preferredembodiments of the present invention are susceptible to variousmodifications, changes, and adaptations, and the same are intended to becomprehended within the meaning and range of equivalents of the appendedclaims.

For example, although the embodiments of the invention have beendescribed above with exemplary materials, the invention is not limitedthereby. Other suitable materials could be used. In particular, althougha thermoplastic medium or curable thermosetting medium may have beendescribed in a particular embodiment, another type of hardenable orcurable material could be used, such as an ultra-violet sensitivematerial.

What is claimed is:
 1. A method of manufacturing an assembly of ribstructures sandwiched between a thin dielectric glass layer and a glasssubstrate for use in a plasma addressed liquid crystal display, themethod comprising: introducing a curable glass frit containing pasteinto cavities in a mold to form the rib structures; forming a thin layerof a dielectric glass frit containing composition on a collector drum;transferring the rib structures from the mold to the dielectric glassfrit containing layer on the collector drum; and transferring the ribstructures and thin dielectric glass frit containing layer from thecollector drum to the glass substrate.
 2. The method according to claim1, wherein the mold is a soft intaglio mold.
 3. The method according toclaim 2, wherein the mold comprises silicone.
 4. The method according toclaim 1, wherein the mold is a film on a rigid substrate, said filmhaving slots formed therein at locations corresponding to the desiredbarrier ribs.
 5. The method according to claim 4, wherein the filmcomprises silicone.
 6. The method according to claim 1, wherein theglass frit containing paste comprises glass frit and a thermoplasticbinder.
 7. The method according to claim 6, wherein the dielectric glassfrit containing composition comprises a dielectric glass frit and athermoplastic binder.
 8. The method according to claim 7, wherein thedielectric glass frit containing layer on the collector drum is heatedto a temperature of from about 40° C. to about 150° C.
 9. The method ofclaim 8, wherein said step of transferring said ribs onto saiddielectric glass frit containing layer comprises pressing said moldagainst said heated dielectric glass frit containing layer on saidcollector drum such that said rib structures contact said dielectricglass frit containing layer, cooling said dielectric glassfrit-containing layer while in contact with said barrier rib structures,and removing said mold.
 10. The method according to claim 1, wherein thethin dielectric glass frit containing layer is from about 15 μm to about50 μm in thickness.
 11. The method according to claim 6, wherein saidrib structures and dielectric glass frit containing layer aretransferred from said collector roll to said substrate by contactingsaid rib structures to said substrate.
 12. The method according to claim11, wherein said substrate is heated to a temperature of from about 40°C. to about 150° C. prior to contacting said rib structures.
 13. Themethod according to claim 1, wherein the forming of a thin layer of adielectric glass frit containing composition on the collector drumcomprises providing a transparent dielectric glass paste onto a polymerfilm on the collector drum.